There is a gap on the market. I couldn't find a WiFi shield with SPI connected ESP8266. It would be connected the same way like Ethernet shields and WiFi shield.

I know two libraries with standard arduino networking API (Server and Client implementation) which support SPI connection. The arduino.org's WiFi Link as used in Primo would need only a small #define modification for AVR. And today I found this WiFiSpi library and firmware.

I really like that the firmware is an Arduino sketch. I think that will make it much easier for people to install the firmware using the Arduino IDE compared to the headaches of trying to flash the AT firmware. And of course this makes it so easy to read the firmware source code and make modifications.

The availability of a shield with the firmware already installed would make it even easier. Using AT commands is attractive when the ESP8266 ships with the AT firmware already installed.

WiFi Link firmware is a sketch too. It has IoT configuration AP concept similar to PersWiFiManager, If the firmware connects to network, the Atmega sketch doesn't need to contain WiFi credentials. And it has Atmega sketch OTA Upload support, but it is not solved for SPI yet.

Of course, both features could by easy added to Jiri Bilek's library with WiFiManager and AVRISP (after solving the slave/master switching of SPI).

The SPI connection requires more wiring then the Serial connection. And more level shifters. So a shield would make it easy for beginners. (And the WiFi Link system requires one more connection for it's slaveReady signal.)

I trusted the statements on stackexchange about esp8266 gpio 5 V tolerance and did leave out the level shifters in my test setup. It works. The Wemos is fine. I wouldn't do that for permanent use, so the shield should have level shifting.

Hi,I am glad you like the library.The main goal was to substitute the buggy-by-nature serial communication with something more reliable. I tried several serial libraries using original AT firmware and at the end I am convinced the AT firmware is not suitable to make a reliable communication when the traffic is not negligible.

If you have any questions or comments, just write.

And big thanks to Juraj for (now still mysterious for me) piece of code

Hi,I am glad you like the library.The main goal was to substitute the buggy-by-nature serial communication with something more reliable. I tried several serial libraries using original AT firmware and at the end I am convinced the AT firmware is not suitable to make a reliable communication when the traffic is not negligible.

If you have any questions or comments, just write.

And big thanks to Juraj for (now still mysterious for me) piece of code

Hello Jiri. Juraj

I am trying to use WiFiSpi inan Arduino DUE connected to a WeMos D1 mini pro wifi module.

I cannot get it to work.

Is the SAM architecture that different?What can I try to tweak to make it work? Data rate divisor? (sam clock is 84MHz and usual divisor constants from AVR maybe do not work)How can I get to this low level details?

I am trying to use WiFiSpi inan Arduino DUE connected to a WeMos D1 mini pro wifi module.

I cannot get it to work.

Is the SAM architecture that different?What can I try to tweak to make it work? Data rate divisor? (sam clock is 84MHz and usual divisor constants from AVR maybe do not work)How can I get to this low level details?

Thanks for your help and support.

first of all - wiring? did you wire MISO, MOSI and clock to the SPI header? do you power the Wemos from Due 3.3 V pin?

You could turn on SPI debugging on ESP8266 app. In file SPICalls.cpp uncomment #define _DEBUG_SPICALLS.But! The option turns on printing in ISR, and it is quite dangerous and should be used only to ensure the data are being read and transmitted. It could cause ESP resets and whatever bad you could imagine

Now, I also found WiFiManager and managed to test it. VERY practical for 'first time setup', without changing the code every time.

I will definitely useit, hence my question:How do I reset the last SSID so to have the wifimanager go into ConnectionAP from my application on DUE?

If I understood correctly, if the last SSID is not found, manager goes into AP automatically. This is OK if I "move" my device from on place to another, with a different wifi network.

What if I simply want to connect to a different wifi?I would like to have a push button on my arduino DUE that would force WiFiManager (included in WiFiSpiESP, who is running on my WeMos D1) to forget the last wifi and go into ConnectionAP.